NZ Govt confirms it won’t test for virus prevalence

Media Statement

8 July 2020

The Government has formally confirmed that it will not use any of the current or future serology tests to assess how widespread the Covid19 disease has been in New Zealand.

In answer to an Official Information Request by the Covid Plan B group, the Director of the COVID-19 Health System Response team in the Ministry of Health said serology tests would underestimate the true level of exposure to Covid-19.

Epidemiologist Simon Thornley says the new policy is the opposite of what was done in 2009 when serology data on low prevalence of swine flu convinced health officials not to take extreme control measures.

“Serology testing will underestimate the true prevalence, but that will be many times more accurate than just guessing from tests of people presenting with symptoms.

“Fear and uncertainty are driven by lack of information. The more we know, the better we can fight disease. It has been the policy in the past, so it’s strange not to do it now.”

Thornley says a consistent picture is emerging that nose tests for Covid-19 are only picking up a small fraction of all cases.

“Antibodies, present in the blood as well as T cell immune responses to the virus are revealing the coronavirus has reached far more people than listed in the daily “cases” statistic.

“That is important because it would reveal the true effectiveness of our protective measures, and the true state of our population immunity to coronavirus.”

In response to the OIA request for data from serology testing, the Government confirmed:

“Currently there are no Ministry sanctioned seroprevalence studies being performed”.

It claimed that this was supported by a letter in the Nature Medicine journal which indicated that one study found variability in individuals; 40% of asymptomatic people became seronegative and 13% of symptomatic people became negative for IgG [An immunoglobulin] as they recovered.

It noted that a study had been undertaken by the Southern DHB, and that “Positive COVID-19 cases from the Southern DHB study will be confirmed on a second assay to increase positive prediction value.” It said “future studies will have to learn from the Southern DHB study and adapt its methodology accordingly.” The Ministry added that there had been blood mononuclear cell collection by the University of Otago which would be used to perform future mediated response testing.

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Contact Simon Thornley 021 299 1752

Erroneous Covid modellers reveal myopic focus

5 June 2020

Media Release

The Covid-19 Plan B group has dismissed as “scaremongering” a claim that an 8% chance of a Covid-19 outbreak under Level 1 means New Zealand should continue in level 2, and restrict large gatherings, based on the risk of spread they pose.

Epidemiologist and Covid-19 Plan B spokesperson Simon Thornley says; “The team that incorrectly forecast 80,000 Covid-19 deaths in New Zealand are back, now claiming that moving down to Level 1 will increase the risk of a large outbreak from 3 to 8 per cent.

“The Plan B group want to underscore that the chance of large outbreaks is low, since the latest evidence, from both immunology studies overseas, and epicurves in many countries strongly suggests that population immunity is high.

“Countries such as China, Taiwan, Switzerland, Slovenia and ourselves that have now recovered from the epidemic have experienced low levels of new cases for several weeks. Slovenia has even opened its borders to travelers from other European Union nations, without the requirement for quarantine.

This is also supported by recent data from Japan, which went lower than New Zealand’s level 2 over 12 days ago. The much more densely populated country than New Zealand has not seen spikes in cases.

Evidence is becoming clearer that enforcing harsh social distancing measures have little to no effect. The Matatini group seem to have ignored these studies, and simply assumed that distancing works.”

Thornley points out that the 8% risk is small compared to all the costs of lockdown that are now apparent, such as deferred health treatment, unemployment, business collapses and public debt.

“The priority now should be to flatten the severe economic recession that is imminent, and return the majority of our country to normal life, while doing our best to protect the vulnerable.”

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Contact: Simon Thornley, mob: 0212991752

Thornley: we should be at Level 1 by now

Cabinet is set to look at whether New Zealand should move to level 1 on June 22, but pressure is mounting to move earlier, with Deputy Prime Minister Winston Peters saying it should have already happened.

Dr Simon Thornley, senior lecturer of public health at Auckland University, told Mike Hosking we should be at level 1 by now.

“A second wave is extremely unlikely.

“Japan have opened up and they haven’t had a second wave and they have a of things against them that we don’t have, like densely populated cities.”

Thornley also says a travel bubble between New Zealand and Australia is now safe.

https://www.newstalkzb.co.nz/on-air/mike-hosking-breakfast/audio/dr-simon-thornley-we-should-be-at-level-1-by-now/

Are the coronavirus epidemiological models any good?

Health issues India discuss coronavirus models with Dr Simon Thornley.

 

How to respond to a spike in COVID-19

Media Statement

17 May 2020

Epidemiologist Simon Thornley says is likely that there will be a rise in COVID-19 cases in New Zealand, so while there is no need to return to national lockdown, protection of vulnerable people is necessary.

“Internationally lockdowns have not prevented subsequent spikes in the number of cases, such as in Hokkaido, Japan. Lockdowns just slow or delay the inevitable resurgence of COVID-19.

“While the evidence does not endorse further lockdowns, even in the face of further cases, the elderly deserve protection. The rest of us can safely get on with our lives.

“I expect COVID-19 to join other coronaviruses such as HCoV-229E, HCoV-HKU1 and HCoV-OC43 as endemic with winter seasonal peaks – when they cause fatalities in rest homes. So, we need to take particular care toward older people and those with co-morbidities.

Thornley says that to justify a renewed lockdown the Government would need to argue health services were at risk, public immunity was low, and the risk to people’s health was major.

“The nation may lack immunity due to lockdown – but we have no information because the Government hasn’t done serology tests. But we do appear to have enough health service capacity, and for most of us the virus poses very little danger.”

There is now compelling evidence that lockdowns in Europe were not especially effective, and that there was no difference in per capital cases and deaths in a comparison of US States. The main factor linked to cases and deaths has been found to be testing rates; the more tests that were carried out by State, the more cases were found.

The risk of future waves is related to our exposure to the virus. Tests of immunity in hard hit countries are returning immunity levels of about 5%, such as in Spain. Other tests of cell mediated immunity suggest higher real levels of immunity than those obtained from antibody tests alone. In Germany, 34% of antibody negative healthy donors showed markers of cellular immunity. The rise, fall and now low number of cases in China, with smaller contained outbreaks after the initial peak, suggest that immunity is sustained, at least in the medium term.

In even hard hit countries the risk of death from the virus for the majority of working age people, especially those under the age of forty, the mortality risk is very low.

Contact: Simon Thornley, 021 299 1752

RETURN TO SCHOOL GIVEN OKAY

26 April 2020

MEDIA RELEASE

Simon Thornley, epidemiologist with the Covid Plan B Group, says parents who need to send their children to school this week should not be fearful, as the chance of exposure to Covid-19 is very low and their chance of being harmed if they catch it is extremely small.

Thornley says in a post to the Plan B website that the risk is not the same for everyone.

“Your risk of dying from the virus is about the same as your risk of dying that year given your age.

“This means that children of school age are extremely low risk for having severe complications from the virus.

“It is very sensible for the government to open schools. I believe that this will help build higher levels of immunity in children to act as barriers for the spread to elderly and those with pre-existing medical conditions. These people are the ones we really want to protect from the virus.

“Modellers have concluded that school closures are unlikely to be an effective strategy for halting Covid-19.”

In a systematic review of scientific studies relating to Covid-19 in children, the authors concluded that children had a much milder response to the virus than for adults. Of three children that required intensive care, all had severe underlying conditions.

In one case-series in China, 90% of test-positive cases had no symptoms attributable to the virus. Of all children, infants are more likely to have severe complications.

One possible objection to returning to school is that adults could catch the infection from children.

“While this is possible, an analysis of cases from Shenzhen, China, shows that attack rates are higher in older adults and the majority of transmission occurs among household contacts.

New Zealand has had a Covid-19 cluster of about 92 students at Marist College in Mount Albert, Auckland. The first identified case was a teacher and 12 students have subsequently tested positive. The majority of cases have been adults and at the time of writing, 79 cases had recovered.

In New Zealand, there is little evidence of risk from spread of infection in children. According to the Ministry of Health, there were 18/344 or 5% of New Zealand’s active cases in people  under the age of 20 years. Overseas data shows that immunity to the virus is building in populations that have been tested.

\ends

ELIMINATION “UNIQUE, BRAVE AND UNNECCESSARY”

24 April 2020

MEDIA RELEASE

Simon Thornley, epidemiologist with the Covid Plan B Group, says the Government’s shift into a hardline elimination or zero spread objective against Covid, is “unique and brave”.

Thornley says he admires the willingness of New Zealanders to undertake a national project that will require tough social restrictions for at least a year, and a nationwide vaccination programme if a vaccine becomes available.

“It is unique and brave; and if any country can do it, New Zealand can.

“The plan rests on tough social restrictions that only end when a vaccine is invented and most of the population is vaccinated.

“Data from the rest of the world suggests that it is unnecessary. We could safely return to our original ‘flatten the curve approach’ of protecting the vulnerable while immunity is gained amongst the healthy population.”

In a post to the Groups website today, Thornley says evidence suggests that it is not true that New Zealand’s population is defenseless and only a lock down is halting the virus.

Serological tests from samples of people in New York, Germany and California, show that between 4 to 15 per cent of the population have seen the virus, recovered from it, and are now immune.

“It shows that the mortality of the virus is much lower than previously appreciated. Also, it demonstrates why a suppression strategy is better than elimination. China, which is trying to eliminate the virus, is now experiencing a resurgence in cases.”

“Recent analysis from the US shows that lockdowns are not effective in reducing Covid-19 deaths. The data shows that the strongest factor determining a State’s Covid-19 deaths is population density. The lower it is, the lower the death rate. This is a key factor in New Zealand’s favour.”

/ends

Health expert says second Covid-19 wave possible

https://www.stuff.co.nz/national/121123046/coronovirus-health-expert-says-second-covid19-wave-possible

Data gives hope for quick end to lockdown

After sparking the first serious debate in New Zealand about the best way of beating Covid-19, Simon Thornley, a member of the Plan B group, explains why he has hope for a safe and swift exit.

There are two approaches offering hope for beating Covid-19.

The Government says the threat is terrible, so elimination is necessary, and that will require a long period of management.

The public health professionals in our group say the threat is major for a small number of people, but we can and must protect them, that the virus wave is abating and immunity growing, and that means we can exit early. Fortunately, that also means hundreds of thousands of people can be saved from economic disaster.

The data shows that internationally and here, the threat of Covid-19 is abating. History will tell us whether this was from lockdown, or immunity growing. That doesn’t matter now, because the data points to the same conclusion: we can shift into what our government calls Level 2.

The major threat is not Covid-19, but the talk of eliminating it and hanging on for a vaccine.

Waiting for a vaccine sounds like soldiers telling each other that their misery will be over by Christmas. But Christmas comes and they are still in the trenches.

As an epidemiologist, I know that vaccines often don’t arrive. I remember the first time I heard that a vaccine for rheumatic fever was five years away. That was ten years ago. There still isn’t one.

Elimination is an impressive goal. We will be the first country in the world to achieve it. But I’m not sure people appreciate what that requires. It is only viable if every person who gets Covid-19 is identified, tested, isolated and quarantined. That’s hard, because at least half of people with Covid-19 don’t know they’ve got it.

I found this out in the recent Auckland measles outbreak. Much of the community were immune, and cases presented in typical fashion. It didn’t end because we stopped it, but because the disease burnt out. People who were susceptible to measles developed immunity, until the disease could no longer spread. For measles, we had additional weapons at our disposal too: we had a reliable test for immunity and a vaccination.

COVID-19 is sneakier than measles. Iceland found out that about half of test-positive cases had no symptoms. Almost 1% of the community tested positive. If the same were true in New Zealand, 50,000 people would now have the virus.

To eliminate the virus we have to find every person and quarantine them to prevent further spread. We’re a small country. We could do it.

But is it worthwhile if population immunity is doing the job? The finding of widespread immunity was an important landmark in the fight against swine flu in 2009. The disease was not as serious as first thought – and immunity was high enough to halt the spread of the virus. A German study showed that in one town, 14% were immune, while 2% had active infection. A similar US study reported that about 3% were immune.

In New Zealand, we don’t know the level of immunity to Covid-19. Perhaps our immunity levels are already high and the virus is being eliminated ‘naturally’. Like swine flu, we need to test for immunity before we take on the Herculean task of eliminating it.

Our hope is that immunity is occurring, because that means New Zealand can exit swiftly. Unfortunately, there are signals that it’s not happening as fast as elsewhere.

Since New Zealand started lockdown, active infections have declined from their peak by 22%, whereas Australia has fallen more steeply (44%).

Since the lockdown, cumulative per capita cases have grown at a greater rate in New Zealand compared to most Australian states (Figure 1). Infected cases have progressively declined for the last three weeks in Australia. Australia has had a much looser definition of lockdown, with 90% of the economy continuing to operate, compared to about 50% here.

This is similar to other countries which have soldiered on, albeit with “distance” practices, such as Sweden, Taiwan, Hong Kong, Iceland, and South Korea.

Let’s address again the threat posed by the virus.

In a conservative estimate, Cambridge statistician David Spiegelhalter noticed that age-related mortality rates from the virus in Wuhan closely matched annual mortality rates in the British population.

His conclusion was that getting the virus is like squeezing one year’s mortality risk into two weeks or so – the duration of the illness.

Whether we like it or not, people aged more than 80 years have a one in ten chance of dying each year – that is similar to their chance of dying with COVID-19.

Yes, there have been “thousands of deaths” as the headlines claim – but these are not unexceptional. Overall mortality is indeed high in Europe because Covid-19 does compromise health, but no higher than observed during the 2016/17 influenza season.

This gives hope that, with our lower population density, the virus is not going to overburden our health system – which was one of the main drivers for the lockdown.

The threat of economic disaster scares me personally just as much as the threat of the virus initially scared me professionally. Rising unemployment, business closure and State benefits remind me of my childhood, deeply affected by Dad’s unemployment and consequential mental health.

My hope is that other kids don’t have to experience what I did. The data shows we don’t need to wait until Christmas – we can emerge from our trenches now.

Simon Thornley, Senior Lecturer Epidemiology and Biostatistics, The University of Auckland.

Note: Figure 1. Cumulative cases (PCR positive) of COVID-19 per million, by days since lockdown, comparing New Zealand with Australian states.

Source: Australian and New Zealand Government statistics.

 

Chaudhuri: The ‘contrarian’ view on Covid-19

An article published on Newsroom this week takes potshots at “contrarian” academics who have chosen to question received wisdom regarding how countries around the world, including New Zealand, are responding to Covid-19.

As one of those “contrarian” academics, I would like to offer some additional perspective.

In an earlier piece for Newsroom “A Different Perspective on Covid-19”, I wrote that no one is suggesting that Covid-19 deaths are not tragic. I pointed out that in focusing on how many people died of the coronavirus around the world every day, we are ignoring the fact that as we devote resources to fight Covid-19, we take those resources away from alternative uses. This diversion will also result in the loss of lives. But those deaths will register less on our collective psyche since they will be diffused, scattered all over the world and will not be reported on in the same breathless manner. I called this the distinction between “identified lives”, deaths that happen right in front of our eyes and within a short span of time, as opposed to the more spread-out loss of “statistical lives” that occur in the background, slowly and inexorably.

The Newsroom article challenging this “contrarian” view and others quotes an infectious disease expert who says: “I’m just opposed to the very fundamental values base that they’re coming from, around how it’s okay to let people die of this because they would die anyway, or something? …This comes down to a values thing and what you’re willing to sacrifice for that.”

I agree. This does come down to a values thing. The position taken by many epidemiologists is this: we will minimise deaths from Covid-19 regardless of the cost. The obvious implication is that this is a comparison of lives lost against dollars saved.

This is completely and utterly untrue.

As I point out in my article, there is a trade-off here. We are going to lose lives no matter what. If we shut down the economy and prevent the disease from spreading, then we save lives that otherwise would have succumbed to Covid-19. But in shutting down our economies, we jeopardise the lives and livelihoods of others.

So, no, this is not about lives versus dollars; it is about lives versus lives.

This is because shutting down the economy has other unforeseen consequences. New Zealand’s unemployment rate could hit 13.5 percent. In the US, it is predicted to climb as high as 26 percent.

Is it so hard to believe that such high rates of unemployment are going to cause poverty, hunger, depression and yes…deaths? It is well-known that unemployment leads to lowered life expectancy. This kind of unemployment tears communities apart and results in long-lasting inequality. It tears at the fabric of our societies, destroys social capital and decimates our shared sense of community.

There are already people struggling with mortgage payments, rent and grocery bills. To what extent these people go under, or not,will depend on the extent of government bail outs. Some countries will do better; others less so.

And, much of this burden is falling and will fall on the socio-economically disadvantaged; the ones who are not able to engage in social distancing; the ones who do not have the luxury of working from home; the ones who are spending four weeks cooped up in cramped spaces without access to unlimited broadband; the ones who live from pay cheque to pay cheque, the ones who need to show up at our supermarkets and hospitals as part of essential services; the ones that need to take public transit in order to do so; the ones who are being exposed to the disease every single day since they have no way out.

The infectious disease specialist goes on to say that some countries are “digging mass graves”. This must refer to countries other than New Zealand since at the time of writing, we have had only nine deaths. Yes, other countries are certainly facing catastrophe but in a far different sense than the one she refers to.

A recent article by Ruchir Sharma in the New York Times sums it up: Some countries face an awful question: death by coronavirus or by hunger?

As Sharma points out, while 15 million people have filed for unemployment benefits in the US, in developing countries more than two billion people are facing unemployment without any social safety net. As of now, nearly 80 countries have approached the IMF for bail-out packages.

What do you think will happen when the healthcare infrastructures of these countries collapse? People will die. They will die of easily preventable diseases like cholera. Children will die due to lack of adequate care or lack of vaccination. Diseases that we thought had been eradicated like measles will come roaring back. Confinement in close quarters, even in countries like New Zealand, is going to lead to a resurgence of tuberculosis; especially among the socio-economically deprived.

Imran Khan, the prime minister of Pakistan, recently said that South Asia is “faced with the stark choice” between “a lockdown” to control the virus and “ensuring that people don’t die of hunger and our economy doesn’t collapse.”

Are these lives worthless? Are these lives not worth saving?

Somehow, it seems to have come to the point where arguing for total lockdown is the enlightened, compassionate view and those questioning the wisdom of lockdowns are heartless philistines.

This is completely untrue. I believe our position is the more thoughtful and rational position; not born out of instinctive gut feelings but arrived at via careful reasoning.

We recognise that we are faced with a crisis. Sure, we need to minimise Covid-19 deaths; but in doing so, let us not jeopardise other lives. And yes, other lives are being jeopardised. We are simply saying that we should be clear-headed about the challenges. In this particular scenario I cannot do better than to appeal to the Benthamite principle of greatest good for the greatest number.

We are also arguing for saving lives; but we are saying let us look for options that minimise lives lost whether from Covid-19 or from our efforts to fight Covid-19.

At the end of the day, it is our position that is more humane and rational. Yes, it is a difference in values; except some are suggesting that some lives are worth saving more than others. We respectfully disagree.

First printed: Newsroom. https://www.newsroom.co.nz/2020/04/16/1130087/the-contrarian-view-on-covid-19